Hat stringers may be used to stiffen structures such as, without limitation, the skin of wings, fuselage, doors or tail sections. Stringers can be fabricated with various cross-sectional shapes such as, without limitation, a hat cross-section. Stringers used on an aircraft wing may be required to conform to the contour of the wing and may have a length of up to 100 feet or longer.
It may be difficult to manufacture a long, narrow structure, such as a hat stringer, which may be highly-contoured and/or have a cross-section which varies along its length. The variations in cross-sectional size and/or shape may have the potential of trapping the structure in any hard mold or mandrel used to maintain the hollow inner shape of the structure during fabrication.
Accordingly, there is a need for a mandrel that may allow it to be more easily removed after a part has been laid-up and/or cured. There is also a need for a method of fabricating composite parts using such a mandrel.